>I don't think it does. The dash seems to be a valid character in the first grouping, and can therefore be in the first position, as in:
>

-a15a-a20
>-1637-b2

>
>Tested with: http://regexpal.com/
>"Your friend in building RegEx pressions." :-)

Thanks, I am trying to use that tool. What happens after we enter the expression and the data. Is there a button somewhere to trigger the validation?